During sea trials it is often required to mount data collection devices, such as video cameras and accompanying cables, to the underwater portion of the hull of a ship. These devices may be mounted in a dry dock. Alternatively, the cables may also be mounted using underwater methods by divers. Some installation methods may be applicable to both dry dock environments and underwater environments.
Regardless of the method in which the cables may be secured to the bull, there is a need for improved cable-mounting when the cable is mounted below the ship's waterline for the purpose of underwater operations. For example, a commonly used method for securing cables to the submerged hull surface is to weld attachment points. The welding may be done in a dry dock scenario or may be carried out by underwater welding. Regardless, these permanent welds are very expensive, not easily reversed, and not always possible since the inside of the vessel must be certified as gas free. Another known method is to cut holes in the ship hull, install a waterproof pass-through, and run the cables directly through from the inside of the hull. This is also expensive, and could risk sinking the vessel.
The implementation of magnetic cable fasteners or guides has been used in non-water-related environments. If implemented for submerged hulls it would be beneficial because magnetic cable fasteners would simplify underwater cable installations. However, the prior art does not teach cable fasteners or guides that are robust enough for either underwater installation, or strong enough to work in after-installation applications, such as when the ship is travelling at operational speeds. For example, the prior art teaches a magnetic cable guide, but this device uses a magnet that only has a magnetic force of 2.2 lbs. This will not work in an underwater environment, as it is not strong enough to hold the cable firmly or to prevent damage by strumming since it does not have internal clamping to firmly hold the cable.
Thus it is desired to have a magnetic cable clamp that robust enough for underwater implementation, that can properly clamp and maintain a cable in position even when exposed to working conditions when the ship is traveling at operational speeds. It is also desired to have a clamp that minimizes hydrodynamic drag and that is not easily pulled off the hull when the ship is in operation. It is also desired to have magnetic clamps that are easily and securely installed and easily removed. It is also desired that the signals traveling through the cable are not disturbed by the magnets.